Tokyo University of Science

About: Tokyo University of Science is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Thin film & Enantioselective synthesis. The organization has 15800 authors who have published 24147 publications receiving 438081 citations. The organization is also known as: Tōkyō Rika Daigaku & Science University of Tokyo.

DNS of turbulent channel flow at very low Reynolds numbers

Abstract: Direct numerical simulation (DNS) of a fully developed turbulent channel flow for very low Reynods numbers has been executed with larger computational box-sizes than those of common DNS. The present Reynolds number is decreased down to Reτ = 64, where Reτ is based on the friction velocity and the channel half width δ. For Reτ=80 with using the largest box of 51.2δ×2δ×22.5δ, the periodic weak-turbulence regions are observed. This type of locally disordered flow is similar to a turbulent puff observed in a transitional pipe flow. Various turbulence statistics such as turbulent intensities, vorticity fluctuations, Reynolds stresses are provided. Especially, their near-wall asymptotic behavior and budget terms of turbulence kinetic energy are obtained and discussed with respect to Reynolds number dependence and an influence of the comptational box-size. In addition, two-point correlation coefficients, visualized instantaneous flow fields and the pre-multiplied energy spectra are presented in order to examine turbulence structures.

Carrier Dynamics in TiO2 and Pt/TiO2 Powders Observed by Femtosecond Time-Resolved Near-Infrared Spectroscopy at a Spectral Region of 0.9−1.5 μm with the Direct Absorption Method

Abstract: Femtosecond time-resolved near-infrared spectra of TiO2 and Pt/TiO2 powders are measured at the wavelength region of 0.9−1.5 μm with the direct absorption method. Broad absorption bands of charge carriers, mainly free and trapped electrons, are observed for TiO2 and Pt/TiO2. The absorption band shape changes with a time constant of 160 fs after the photoirradiation, which most probably reflects the trapping of the generated free electrons. Population decay curves of the carriers after 1 ps, obtained for three different pump light powers, are well-explained by the second-order decay kinetics with a common second-order rate constant, indicating nongeminate recombination of the electron−hole pairs. When Pt is loaded to TiO2, an additional decaying process of 2.3 ps is observed. This decay component represents the transfer of generated electrons from TiO2 to Pt, which is consistent with the known increase of overall catalytic activities by the Pt cocatalyst.

Tomato FRUITFULL homologues act in fruit ripening via forming MADS-box transcription factor complexes with RIN

Abstract: The tomato MADS-box transcription factor RIN acts as a master regulator of fruit ripening. Here, we identified MADS-box proteins that interact with RIN; we also provide evidence that these proteins act in the regulation of fruit ripening. We conducted a yeast two-hybrid screen of a cDNA library from ripening fruit, for genes encoding proteins that bind to RIN. The screen identified two MADS-box genes, FUL1 and FUL2 (previously called TDR4 and SlMBP7), both of which have high sequence similarity to Arabidopsis FRUITFULL. Expression analyses revealed that the FUL1 mRNA and FUL1 protein accumulate in a ripening-specific manner in tomato fruits and FUL2 mRNA and protein accumulate at the pre-ripening stage and throughout ripening. Biochemical analyses confirmed that FUL1 and FUL2 form heterodimers with RIN; this interaction required the FUL1 and FUL2 C-terminal domains. Also, the heterodimers bind to a typical target DNA motif for MADS-box proteins. Chromatin immunoprecipitation assays revealed that FUL1 and FUL2 bind to genomic sites that were previously identified as RIN-target sites, such as the promoter regions of ACS2, ACS4 and RIN. These findings suggest that RIN forms complexes with FUL1 and FUL2 and these complexes regulate expression of ripening-related genes. In addition to the functional redundancy between FUL1 and FUL2, we also found they have potentially divergent roles in transcriptional regulation, including a difference in genomic target sites.

Depth of Ultra High Energy Cosmic Ray Induced Air Shower Maxima Measured by the Telescope Array Black Rock and Long Ridge FADC Fluorescence Detectors and Surface Array in Hybrid Mode

Abstract: The Telescope Array observatory utilizes fluorescence detectors and surface detectors to observe air showers produced by ultra high energy cosmic rays in the Earth's atmosphere Cosmic ray events observed in this way are termed hybrid data The depth of air shower maximum is related to the mass of the primary particle that generates the shower This paper reports on shower maxima data collected over 85 years using the Black Rock Mesa and Long Ridge fluorescence detectors in conjunction with the array of surface detectors We compare the means and standard deviations of the observed $X_{\mathrm{max}}$ distributions with Monte Carlo $X_{\mathrm{max}}$ distributions of unmixed protons, helium, nitrogen, and iron, all generated using the QGSJet~II-04 hadronic model We also perform an unbinned maximum likelihood test of the observed data, which is subjected to variable systematic shifting of the data $X_{\mathrm{max}}$ distributions to allow us to test the full distributions, and compare them to the Monte Carlo to see which elements are not compatible with the observed data For all energy bins, QGSJet~II-04 protons are found to be compatible with Telescope Array hybrid data at the 95% confidence level after some systematic $X_{\mathrm{max}}$ shifting of the data Three other QGSJet~II-04 elements are found to be compatible using the same test procedure in an energy range limited to the highest energies where data statistics are sparse